- Efficient synthesis of selenoureas from the corresponding carbodiimides
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Selenoureas were synthesized by the reaction of carbodiimides with LiA1HSeH in the presence of hydrogen chloride.
- Koketsu, Mamoru,Takakura, Naotaka,Ishihara, Hideharu
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- Tunable NIR-II emitting silver chalcogenide quantum dots using thio/selenourea precursors: Preparation of an MRI/NIR-II multimodal imaging agent
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Aqueous-stable, Cd- and Pb-free colloidal quantum dots with fluorescence properties in the second near-infrared region (NIR-II, 1000-1400) are highly desirable for non-invasive deep-tissue optical imaging and biosensing. The low band-gap semiconductor, silver chalcogenide, offers a non-toxic and stable alternative to existing Pd, As, Hg and Cd-based NIR-II colloidal quantum dots (QDs). We report facile access to NIR-II emission windows with Ag2X (X = S, Se) QDs using easy-to-prepare thio/selenourea precursors and their analogues. The aqueous phase transfer of these QDs with a high conservation of fluorescence quantum yield (retention up to ~90%) and colloidal stability is demonstrated. A bimodal NIR-II/MRI contrast agent with a tunable fluorescence and high T1 relaxivity of 408 mM-1 s-1 per QD (size ~ 2.2 nm) and 990 mM-1 s-1 per QD (size ~ 4.2 nm) has been prepared by grafting 50 and 120 monoaqua Gd(iii) complexes respectively to two differently sized Ag2S QDs. The size of the nanocrystals is crucial for tuning the Gd payload and the relaxivity.
- Basel, Siddhant,Bhardwaj, Karishma,Borthakur, Sukanya,Brito, Beatriz,Clarke, Mitchell,Pariyar, Anand,Pradhan, Sajan,Roy, Pankaj,Saikia, Lakshi,Shankar, Amit,Stasiuk, Graeme J.,Tamang, Sudarsan,Thapa, Surakcha
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supporting information
p. 15425 - 15432
(2020/11/18)
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- Selenoureas for anion binding as molecular logic gates
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The first example of a molecular logic gate based on selenourea/anion host-guest interaction that performs a ternary logic operation using an 1H-NMR easy to read response output is described here. Selenoureas are very versatile receptors for anion binding, capable of forming both mono- and bi-coordinated adducts at room temperature in solution.
- Casula, Arianna,Begines, Paloma,Bettoschi, Alexandre,Fernandez-Bola?os, Josè G.,Isaia, Francesco,Lippolis, Vito,López, óscar,Picci, Giacomo,Andrea Scorciapino,Caltagirone, Claudia
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supporting information
p. 11869 - 11872
(2017/11/06)
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- Polyfused nitrogen-containing heterocycles 23.* Methyl 4-hydroxy-3-phenyl-5-phenyl(alkyl)-2-phenyliminoselenazolidine-4-carboxylates and selenazolo[3,4-a]quinoxalin-4(5H)-one derivatives on their basis
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Condensation of methyl phenyl(alkyl)halopyrotartrates with N, N'-diphenylselenourea leads to the formation of methyl 4-hydroxy-3-phenyl-5- phenyl(alkyl)-2-phenyliminoselenazolidine-4-carboxylates, which undergo reaction with 1,2-phenylenediamines to give selenazolo-[3,4-a]quinoxalin-4(5H)-ones. ; 2009 Springer Science+Business Media, Inc.
- Mamedov,Zhukova,Gubaidullin,Beschastnova,I. Kh. Rizvanov,Ya. A. Levin,Litvinov
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experimental part
p. 1294 - 1302
(2010/10/04)
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